Boeing’s 787 Takes Flight to Assess New Battery

A Boeing 787 flew for nearly two hours on Friday in a flight that wrapped up the company’s tests of modifications meant to prevent fires in its lithium-ion batteries.

The company said it would analyze the results of several weeks of testing, which included blowing up the batteries in labs, and then forward the results to the Federal Aviation Administration, probably early next week. Aviation analysts said the F.A.A., which has overseen the testing, could approve the changes later this month if no other problems surface, and the planes, which have been grounded since mid-January, could be flying again in May.

Boeing has “a very good chance” of winning federal certification for its fixes, said Richard L. Aboulafia, an analyst at the Teal Group in Fairfax, Va. But, he said, “there is a lot of political and regulatory uncertainty that could get in the way.”

The National Transportation Safety Board, which has been investigating a battery fire on a 787 parked in Boston on Jan. 7, plans to hold a public forum on Thursday and Friday on transportation uses of lithium-ion batteries, which are more volatile than traditional designs. On April 23 and 24, it will hold a hearing on its investigation into the Boston fire and the deficiencies in the F.A.A.’s initial review of the batteries several years ago.

Those hearings could add to a sense of political caution at the F.A.A., though its engineers have said they believe that Boeing’s changes are working. “And this is all complicated by the fact that Boeing doubled down on this approach and does not have a backup plan,” Mr. Aboulafia said.

The innovative planes were grounded worldwide after a 787 made an emergency landing in Japan with a smoking battery just nine days after the fire in Boston.

Aviation analysts estimate that Boeing and several airline customers could lose hundreds of millions of dollars as a result of the grounding, and Boeing is pushing to get the planes back in the air. Investors are also optimistic. Boeing’s stock rose $1.22 to close at $86.17 on Friday, adding to a rally that began after the F.A.A. approved the testing plan last month.

Boeing said the plane flown in Friday’s test was awaiting delivery to LOT Polish Airlines. The jet left Paine Field in Everett, Wash., at 10:39 a.m. Pacific time with a crew of 11, including two representatives from the F.A.A. The airplane flew for 1 hour 49 minutes, landing back at the field at 12:28 p.m.

Boeing said the flight was meant to demonstrate that the new battery system would work as expected during normal and abnormal flight conditions, though it did not specify the range of conditions it tested.

It said that the test flight was uneventful and that it would deliver the data to the F.A.A. “in the coming days.”

The F.A.A. approved more than 20 types of tests to determine if the new battery system would virtually eliminate the risk of battery fires, as Boeing says it will.

Federal investigators have said that one cell short-circuited in the battery on the plane in Boston and that the short cascaded through the seven other cells, setting off the fire.

Boeing has said that its new battery system has better insulation around the eight cells and between the cells and the casing. It also has a gentler charger to minimize stress and a new titanium system to vent any smoke or heat out of the plane to keep the batteries from getting too hot.

The insulation, made of heat-resistant glass fibers, is supposed to keep a short in one cell from spreading to others. Boeing said the two batteries on each plane would be sealed inside steel boxes that would limit the amount of oxygen nearby to minimize any chance of fire.

Most of the tests have been conducted inside Boeing labs. Friday’s flight was the only one to test the performance of the new batteries in the air. Boeing recently flew two other flights to test other systems on the plane.

The batteries are used to start the planes and to provide power on the ground. Boeing has said that it needs only a single test flight since the batteries are not normally used in flight.

If the plan is approved, Boeing and the airlines will have to monitor the batteries closely for many months. The safety board has said Boeing grossly miscalculated the odds of hazards with the original battery system. It also now has to persuade travelers that the new system is safe.

A version of this article appears in print on , on Page B1 of the New York edition with the headline: Boeing’s 787 Takes Flight To Assess New Battery. Order Reprints | Today’s Paper | Subscribe